Israel has stepped up its campaign against Tehran-backed militant group Hezbollah, whose rocket attacks on March 2 pulled Lebanon into the regional war, triggered by US-Israeli strikes on Iran.

Citing the health ministry, Lebanon's official National News Agency (NNA) said four people were killed in an "Israeli enemy raid" on the town of Adloun, and another two in a strike on an apartment in the Mieh Mieh refugee camp that left four others wounded.

In another area of southern Lebanon, the NNA earlier said an Israeli raid on the town of Habboush killed at least three people and wounded 18 others.

There was no immediate comment from the Israeli military, which earlier warned of an imminent attack on Beirut's southern suburbs, a Hezbollah stronghold that has been targeted multiple times during the war.

Military spokesman Avichay Adraee said in a statement posted online that Israeli forces were targeting Hezbollah's "military infrastructure... throughout the suburb with increasing force".

"For your safety, you must evacuate immediately," Adraee told residents.

Israel, which occupied southern Lebanon for nearly two decades until 2000, has said its military would take control of the border area up to the Litani river, around 30 kilometres (20 miles) from the frontier.

The Israeli campaign has killed at least 1,072 people in Lebanon, with more than one million people displaced, according to Lebanese authorities.

In northern Israel, where repeated air raid sirens have sent residents to shelters, a woman was killed on Tuesday following rocket fire from Lebanon, Israeli authorities said.